US2627789A

US2627789A - Suction box

Info

Publication number: US2627789A
Application number: US154993A
Authority: US
Inventors: Campbell John
Original assignee: Individual
Current assignee: Individual
Priority date: 1950-04-10
Filing date: 1950-04-10
Publication date: 1953-02-10
Anticipated expiration: 1970-02-10

Description

J. CAMPBELL Feb. 10, 1953 SUCTION BOX 3 Sheets-Sheet 1 Filed April 10, 1950 Fe'bi 10, 1953 J M L 2,627,789

SUCTION BOX Filed April 10, 1950 3 Sheets-Sheet 3 mi ir/m/w/mmwrrl INVENTOR."

Patented Feb. 10, 1953 UNITED STATES TENT OF Claims.

This invention relates to an improved vacuum or suction box used in paper making machinery, and that portion of the mechanism used in extracting water from pulp conveyed by an endless wire or felt belt.

The general object of this invention is to provide a novel and improved suction box so that the endless wire or felt belt will be conveyed over the top of the suction box with the minimum amount of friction which is the chief cause of wear and strain on the endless wire or felt belt by the commonly used type of suction box.

A further object of this invention is to provide an improved seal along the edges of the endless wire or felt belt during the interval of passage over the top of the suction box.

Other objects of the invention will be in part pointed out in the following detailed disclosure of an illustrative but preferred embodiment of the invention and will be in part obvious as the disclosure proceeds.

The invention accordingly comprises the features of construction, combination of elements and arrangement of parts which will be exemplified in the construction hereinafter set forth and the scope of the application of which will be indicated in the claims.

For a more comprehensive disclosure of the nature, objects and advantages of the invention reference is had to the following detailed description, and to the accompanying drawings, in which:

Fig. .1 is a partially diagrammatical Vertical general view of the paper forming section of a paper machine, showing the endless wire belt and the improved suction box.

Fig. 2 is a fragmentary plan view of the improved suction box with the endless belt, end seals and side seals removed.

Fig. 3 is a fragmentary vertical longitudinal sectional view of the suction box taken along the line 33 of Fig. 2.

Fig. 4 is a fragmentary vertical longitudinal sectional view of the suction box taken along line 44 of Fig. 2 with the end and side seals added and .also showing the endless wire belt.

Fig. 5 is a sectional and perspective view of the seal assembly consisting of the two side seals and one end seal.

Fig. 6 is a vertical sectional view taken along line 66 of Fig. 2 showing the water seal under the grooved end of a carrying roll and also a section of the endless wire belt.

Fig. 7 is a fragmentary enlarged transverse sectional View of one of the carrying rolls in Fig. 2

showing the anti-friction facing on the carrying roll and also on the bearing surface.

Fig. 8 is a fragmentary longitudinal vertical section through a carrying roll, parts being in elevation, showing ,a modification of Fig. .6.

Figs. 9 and 10 are plan views of modified forms of carrying rolls corresponding to carrying rolls shown in Fig. 2.

Referring to the drawings for a detailed .description of the illustrative embodiment of the invention there shown, improvements have been incorporated in the suction .box in common use on the Fourdrinier machine and well known in the paper industry. Fig. .2 is a plan, with the endless belt, end seals and side seals removed, showing the Fourdrinier wire carrying rolls 1 which in this embodiment .are straight grooved rolls which is a type of carrying roll having annular grooves .in a plane at right angles to the axis of the roll; these rolls are partly encased in the suction box top "2 in which are a number of holes 3 which are staggered, through which the water, sucked from the pulp on the wire, passes into the box 4 (Figs. 1 and 3) below from which it is continually removed.

The carrying rolls may be covered with an antifriction facing 5 (Fig. '7) which may be of resilient mate-rial such as rubber which is lubricated by water. The carrying rolls rotate in bearings 6 (Fig. 7) on the .suction box top :2 (Figs. 2 and 7). The surfaces of the bearings contacting themtating carrying rolls may also be covered with an anti-friction facing l (Fig. 7) which may also be of resilient material such as rubber. On the other hand the bearings might be constructed of a very hard material lubricated by'water such as the wood known as lignum vitae (Fig. 3). Where the carrying rolls have straight grooves substantially throughout the entire length, water sucked out from the layer of pulp on the wire can be discharged through holes 3 in the bearings, as well as those holes '3 between the bearings, into the box t below; these holes in the bearings are under each groove in the carrying roll, and due .to the fact that the straight grooves'in eachsuoceeding carrying roll are not in aline parallel to the edge of the wire but are sta gered, consequently the holes in one bearing will not .be directlyin front or behind the holes in the bearing immediatelyon each side of it but will be offset from each. Water discharged through .the bearing will also help to lubricate the bearing if the anti-friction facing on the carrying rolls or hearings or both is .of the type that water will act-asa lubricant.

Although I have described one Way of reducing friction between the carrying rolls l and the bearings 6, it is also possible for the carrying rolls to rotate in anti-friction bearings which may be of the roller or ball bearing type.

The depth of the bearings is such that when the carrying rolls are rotated they will not jump out of the bearings and to prevent this there are two extra auxiliary bearings 9 carrying the shaft l at each end of the carrying rolls. These extra bearings also help to level the carrying rolls in the bearings on the top of the suction box. The carrying rolls may be driven by a train of gears H keyed on to the shafts Ill. In order that all the carrying rolls 1 rotate in the same direction there are idler gears Ila between each of the main gears II. To prevent shafts H] from twisting by the driving torque there are auxiliary bearings 12 on the outside of the gears. The gears may be driven by any suitable arrangement either from a rotating member on the paper machine or by an individual motor not shown in the drawing. In order to prevent air leakage along the faces of the bearings 6 there is at each end of each bearing a packing gland (3 (Fig. 2) which consists of a small cavity recessed in each bearing; the cavity is filled with a suitable packing material which is held in place by a plate M (Fig. 4) which is screwed into the side of the suction box.

The openings under the two edges of the endless wire belt above the top of the suction box and the outside carrying rolls are closed with sealing strips l5 (Fig. 4) which may be made of or covered with resilient material such as rubber. Because the carrying rolls have straight grooves at their ends under the edges of the endless belt the sealing strips can be made to fit into and across the grooves of each carrying roll and thus make a continuous end seal between the two outside carrying rolls, the top of the suction box and the under edge of the wire as shown in Figs. 4, 6 and 8. If the end seals be made to cover the end portions of carrying rolls as shown at l5 (Fig. 6 and Fig. 8) then the innermost edge of the seals should be tapered down to the top of the carrying rolls as shown at I6 (Figs. 6 and 8). On the other hand if the height of the end seals is made flush with the top of the carrying rolls no tapering of the inside edges of the seals would be necessary. The end seals may be made in units of various widths so as to take care of any width of pulp layer on the wire. Since the surfaces in the annular grooves at each end of the carrying rolls are in a plane at right angles to the axes of these rolls, these surfaces give excellent support to the end sealing strips at the top at each end of the suction box against atmospheric pressure when there is a partial vacuum in the space bounded by the top of the suction box, that portion of the endless belt immediately above the top of the suction box, the seals at the two ends at the top of the suction box, and the seals .along the two sides at the top of the suction box. In both ends of suction box 4 (Fig. 6 and Fig. 8)

there is a shelf I! which can be sealed off by a rubber seal H3. The rubber seal 18 can be placed in any position on the shelf by means of the rod 19 through the handle 20. The commonly used paper machine suction box has this device so that the vacuum in the suction box can be adjusted to the different widths of pulp layer on the wire. If the rubber seal 18 on the shelf ll be adjusted to position as shown in Fig. 6 and Fig. 8, the shelf can be filled with water through the pipe 2| till the height of the water fills the lower spaces of the straight grooved carrying rolls; then if the surfaces of the end seals or the surfaces of the straight grooved rolls, or both, are such that water will lubricate them then such water can be supplied in above manner.

Along the sides of the suction box top where the endless wire belt 22 is carried by the first and last straight grooved rolls there are side sealing strips 23 (Fig. 4 and Fig. 5) which may be made of or covered with an anti-friction material which may be resilient such as rubber. These sealing strips extend along the side edges of the suction box top from one end to th other and sea1 the spaces between the outside surfaces of the first and last carrying rolls and the top outside edges of the suction box.

Although in the above illustrative embodiment of the invention, carrying rolls having straight grooves substantially throughout their length are shown in Fig. 2 it may be even desirable to substitute some or all of the rolls with carrying rolls of types shown in Fig. 9 and/or Fig. 10. Fig. 9 shows a carrying roll with straight grooves near both ends to support the end seals and spiral grooves in between to support the remaining width of the endless belt. This typ of roll will help to keep the portion of the endless belt that is under vacuum taut between the two edges; while Fig. 10 shows a carrying roll with straight grooves near both ends to support the end seals and in between a plain roll 25 to support the remaining width of the endless belt. This type of roll is useful as an aid to the Vacuum in the suction box to remove water from the wet pulp on the wire when the water removal from the pulp becomes more dificult.

It may be also desirable to support carrying rolls in bearings under the end seals as shown in Fig. 8 which is a longitudinal vertical section similar to Fig. 6 except that there is no vertical support for the carrying rolls between the bearings under the seals at the ends of the carrying rolls. In this type of construction it is possible to substitute some or all of the carrying rolls on the improved suction box with the type of carrying rolls disclosed above, and as well, the carrying roll of type shown in Fig. 8 which is a carrying roll having straight grooves near both ends for the support of the end seals while the remainder of the roll between the end seals is made up of a cylinder of woven mesh 25 similar to a dandy roll. This type of roll will prevent disturbance of the matted pulp on the endless belt when large quantities of water on the belt are being removed by the vacuum in the suction box.

A detailed description illustrative of the operation of the improved suction box in removing water from the mixture of pulp and water on an endless belt on a paper machine is as follows:

The Fourdrinier wire, generally called the wire on which the pulp is formed into substantially a thin continuous layer on a Fourdrinier paper machine, is an endless wire screen belt composed of fine wires made of metal such as acid resisting bronze in the case of the warp wires and possibly brass in the case of the filler wires. This endless belt which may vary in length on different paper machines from under 60 feet to over feet long and may be of any width from under 36 inches to over 360 inches wide, rotates between two large rolls, one known as the breast roll and the other the couch roll. The top portion of the belt 22 (Fig. 1) is substantially horizontal or slightly inclined down as it travels from the breast roll 26 to the couch roll 21, and is supported in this position by a number of rotating carrying rolls 28. After passing around the couch roll, the belt is guided back to the breast roll under the top portion of the belt by a number of rotating guide rolls 29, and is kept taut by a stretch roll 39. The couch roll drives the Fourdrinier wire 22 which in turn rotates the breast roll, the carrying rolls, guide rolls and stretch roll.

A mixture of pulp and water is discharged on to the fiat portion of the Fourdrinier wire just as it leaves the breast roll. The improved suction boxes can be placed at a position under the wire where no water has as yet drained from the wire or at a position where some water has drained from the wire; the wire will be carried over the top of these suction boxes by the carrying rolls. Although I have described these carrying rolls as being driven by other means than by the Fourdrinier wire, I do not want to exclude the possibility of rotating them by the Fourdrim'er wire.

To form the pulp sheet, a mixture of pulp and water, for example 99.5 per cent water and .5 per cent pulp, is discharged evenly across the full width of the Fourdrinier wire at the breast roll by means of a long narrow slot 3! or orifice which is adjustable; the pulp and water mixture is prevented from running over the edges of the Fourdrinier wire near the breast roll by a barrier on each edge, usually called the deckle. When the pulp andwater mixture is carried by the Fourdrinier wire over the top of the improved suction box, the portion of the Fourdrinier wire immediately above the suction box tends to seal off the top of the suction box from atmospheric pressure; the space between the Fourdrinier wire and the top of the suction box is substantially sealed at the top ends of the suction box by the seals fitting into and across the annular grooves near the ends of the carrying rolls, and by the packing glands near the ends of the carrying rolls; also the above space is substantially sealed at the top sides of the suction box by sealing strips which extend the full length of each side of the suction box and close the gaps between the outside carrying rolls and the top side edges of the suction box. Air in the above sealed space and in the suction box can be removed by the vacuum pump P (Fig. 1) through the pipes 32 which connect the pump to the suction box 4. Water sucked from the pulp on the Fourdrinier wire falling into the suction box 4 is discharged from the box through pipe 33.

Since certain changes may be made in the above construction and difierent embodiments of the invention could be made without departing from the scope thereof, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

Having described my invention, what I claim as new and desire by Letters Patent is:

1. A suction box provided with a top for use with an endless wire or felt belt in the formation of fibrous webs, comprising in combination, a plurality of carrying rolls which serve to support said belt thereon, said rolls positioned transversely of the box and in spaced relation to each other, bearing members for rotatably supporting said carrying rolls supported on said box top, a plurality of straight grooves positioned adjacent to each of the respective ends of said carrying rolls, end sealing members extending the substantial width of said box positioned adjacent'to each of the ends of said carrying rolls and overlying the endmost grooves, side sealing members extending the substantial length of said box located in overlying relation to a portion of each of the outermost positioned carrying rolls, said end and side sealing members provided with a plurality of flange elements positioned in cooperative relation with the straight grooves of said carrying rolls, which elements extend within and across said grooves of said carrying rolls.

2. A suction box of the character defined in claim 1 wherein the carrying rolls are provided with anti-friction facings.

3. A suction box of the character defined in claim 1 wherein the bearing members areprovided with anti-friction facings.

4. A suction box of the character defined in claim 1 wherein at least one of the carrying rolls is provided with a spiral groove positioned intermediate the straight grooves.

5. A suction box of the character defined in claim 1 wherein at least one of the carrying rolls is formed of a woven mesh cylinder extending the substantial length of the roll between th straight grooves.

6. A suction box provided with a top for use with an endless wire or felt belt in the formation of fibrous webs, comprising in combination, a plurality of carrying rolls which serve to support said belt thereon, said rolls positionedtransversely of the box and in spaced relation to each other, bearing members for rotatably sup porting said carrying rolls supported on said box top, a plurality of straight grooves positioned adjacent to each of the respective ends of said carrying rolls, end sealing members extend-- ing the substantial width of said box positioned adjacent to each of the ends of said carrying rolls and overlying th endmost grooves, side sealing members extending the substantial length of said box located in overlying relation to a portion of each of the outermost positioned carrying rolls, said end and side sealing members provided with a plurality of flange elements positioned in cooperative relation with the straight grooves of said carrying rolls, which elements extend within and across said grooves of said carrying rolls, said suction box top provided with a plurality of discharge apertures positioned between adjacently positioned carrying rolls and spaced throughout the length of said top.

7. A suction box provided with a top for use with an endless wire or felt belt in the formation of fibrous webs, comprising in combination, a plurality of carrying rolls which serve to support said belt thereon, said rolls positioned transversely of the box and in spaced relation to each other, bearing members for rotatably supporting said carrying rolls supported on said box top, a plurality of straight grooves positioned adjacent to each of the respective ends of said carrying rolls, end sealing members extending the substantial Width of said box positioned adjacent to each of the ends of said carrying rolls and overlying the endmost grooves, side sealing members extending the substantial length of said box located in overlying relation to a portion of each of the outermost positioned carrying rolls, said end and side sealing members provided with a plurality of flange elements positioned in cooperative relation with the straight grooves of said carrying rolls, which elements extend within and across said grooves of said carrying rolls, and said bearing members provided with discharge passages positioned beneath said carrying rolls.

8. A suction box provided with a top for use with an endless wire or felt belt in the formation of fibrous webs, comprising in combination, a plurality of carrying rolls which serve to support said belt thereon, said rolls positioned transversely of the box and in spaced relation to each other, bearing members for rotatably supporting said carrying rolls supported by said box top and extending substantially the length thereof, a plurality of straight grooves positioned in spaced relationship throughout the length of said carrying rolls intermediate the substantial ends thereof, end sealing members extending the substantial width of said box positioned adjacent to each of the ends of said carrying rolls and overlying the endmost grooves, side sealing members extending the substantial length of said box located in overlying relation to a portion of each of the outermost positioned carrying rolls, said end and side sealing members provided-with a plurality of flange elements positioned in cooperative relation with the straight grooves of said carrying rolls, which elements extend within and across said grooves of said carrying rolls.

9. A suction box provided with a top for use with an endless wire or felt belt in the formation of fibrous webs, comprising in combination, a plurality of carrying rolls which serve to support said belt thereon, said rolls positioned transversely of the box and in spaced relation to each other, bearing members for rotatably supporting said carrying rolls supported by said box top and extending substantially the length thereof, a plurality of straight grooves positioned in spaced relationship throughout the length of said carrying rolls intermediate the substantial ends thereof, and sealing members extending the substantial width of said box positioned adjacent to each of the ends of said carrying rolls and overlying the endmost grooves, said sealing members provided with a plurality of flange elements which extend within and across the straight grooves of said carrying rolls.

10. A suction box provided with a top for use with an endless wire or felt belt in the formation of fibrous webs, comprising in combination, a plurality of carrying rolls which serve to support said belt thereon, said rolls positioned transversely of the box and in spaced relation to each other, bearing members for rotatably supporting said carrying rolls located on the upper surface of said box top and extending substantially the length thereof, a plurality of straight grooves positioned in spaced relationship throughout the length of said carrying rolls intermediate the substantial ends thereof, sealing members extending the substantial length of said box at the sides thereof positioned in overlying relationship to a portion of each of the outermost positioned carrying rolls, said sealing members provided with a plurality of flange elements which extend within and across the straight grooves of said carrying rolls.

JOHN CAMPBELL.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 644,832 Shearer Mar. 6, 1900 1,521,659 Ullgren Jan. 6, 1925 1,572,238 Jones Feb. 9, 1926 1,791,065 Severini Feb. 3, 1931 1,791,535 Peebles Feb. 10, 1931 2,245,109 Lapeyrouse June 10, 1941 FOREIGN PATENTS Number Country Date 404,530 Great Britain Jan. 18, 1934 457 ,632 Great Britain Dec. 2, 1936 502,183 Great Britain Mar. 14, 1939 277,384 Germany Aug. 12, 1914